According to the manufacturer, the battery for the SimplyGo is approved for use in-flight. However, it's important to understand that regulations regarding these types of batteries can change. Before traveling, it's important to check with the airline to see if they have any internal policies which would prevent the use of this product while in-flight.
Battery LED Charge Indicators
To view the current charge on the battery directly, press the black button on the battery to enable the LED indicators.